Resilient Distributed Dataset (RDD) [RDD]

RDD was the primary user-facing API in Spark since its inception. At the core, an RDD is an immutable distributed collection of elements of your data, partitioned across nodes in your cluster that can be operated in parallel with a low-level API that offers transformations and actions.

5 Reasons on When to use RDDs

You want low-level transformation and actions and control on your dataset;